The Zagros lie on the boundary between the Arabian Plate and the Eurasian
Plate (or a subset of it sometimes identified as the Iran Plate).
Indeed they were formed as the Arabian plate push northwest into the Eurasian
plate during the Miocene epoch between 40 million years ago and 18 million
years ago, finally closing the Tethys Sea.

It is safe to say that the Zagros are more important to human history
than even Mesopotamia just to the west: This is where agriculture
first developed1. The wild varieties of grassy plants
such as wheat, barley, oats, and flax, now staples of agriculture,
are native to the region. People stopped gathering wild wheat and
started planting it in the valleys of the Zagros between 12,000 and 10,000
years ago, at the end of the last Ice Age.

When further climate change forced these people out of the mountains
and down into Mesopotamia, requiring large-scale irrigation projects,
and large-scale organization of manpower, civilization was born.

Throughout ancient times, various peoples thundered down out of the
Zagros to plunder Mesopotamia: the Akkadians, Guti, Kassites, Mittani,
Elamites, Assyrians, and finally the Medes and Persians.
The Assyrian capital, Nineveh (now Mosul), was in the western foothills
of the Zagros, as was a major Elamite and Persian city, Susa, (now Shush). The
Median capital, Ecbatana (now Hamadan), was on Zagros' eastern slopes,
and the Persian capital, Persepolis, lies in a high valley in the southern Zagros.

The recent history of the Zagros has been a sad one: It was the principal
theater of the bloody 1980-1989Iran-Iraq War.